Open Access

Using Short-Term Preoperative Endocrine Therapy to Inform Adjuvant Treatment Choices in Premenopausal HR-Positive HER2-Negative Breast Cancer

4 Phd. Associate Professor of Oncology, Onkogematology And Radiation Oncology Department. Tashkent State of Medical University. Uzbekistan
4 Medical Oncology. Republican Specialized Scientific and Practical Medical Center of Oncology and Radiology, Tashkent, Republic of Uzbekistan
4 Аssistаnt Оf Thе Dераrtmеnt Оf Оnсоlоgу, Onkogematology And Radiation Oncology. Tаshkеnt Stаtе Mеdiсаl Univеrsitу, Tаshkеnt, Uzbеkistаn

Abstract

Limited access to genomic testing necessitates alternative approaches to guide adjuvant treatment decisions in patients with early-stage luminal HER2-negative breast cancer. Studies such as IMPACT and POETIC have demonstrated that a reduction in Ki-67 to ≤10% after a short (2–4 weeks) course of endocrine therapy (ET) is associated with favorable prognosis in postmenopausal patients. In some cases, this allows omission of chemotherapy (CT), thereby avoiding its toxicity. However, evidence for this strategy in premenopausal patients remains scarce.

Objective: To evaluate the impact of a short preoperative “test” course of endocrine therapy on subsequent treatment decisions in premenopausal women with primary operable luminal HER2-negative breast cancer (T1–3N0–1M0).

Materials and Methods: A retrospective analysis was conducted including premenopausal patients treated at Center of Oncology Uzbekistan between 2020 and 2023. All patients had operable luminal HER2-negative breast cancer and received a 2–4 week course of neoadjuvant endocrine therapy prior to surgery.

Results: A total of 250 patients were analyzed. The mean age was 44±6 years. Among patients with initially elevated Ki-67 (>10%), 19.2% demonstrated a reduction to ≤10% after endocrine therapy. Independent predictors of response included age ≥50 years and baseline Ki-67 <30% (p<0.01). According to the PREDICT model, 37.2% of patients had a high expected benefit (>5%) from chemotherapy; however, 20.4% of these patients were able to avoid chemotherapy following Ki-67 reduction. Conversely, among patients with low expected benefit from chemotherapy, 25.6% still received it.

Conclusion: A short “test” course of endocrine therapy in premenopausal patients with luminal HER2-negative breast cancer represents a feasible and reproducible tool for personalizing adjuvant treatment strategies. Further prospective validation is required.

Keywords

References

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